Java http请求封装工具类代码实例

java实现http请求的方法常用有两种，一种则是通过java自带的标准类httpurlconnection去实现，另一种是通过apache的httpclient去实现。

本文用httpclient去实现，需要导入httpclient和httpcore两个jar包，测试时用的httpclient-4.5.1和httpcore-4.4.3。

httpmethod.java

package demo;
public enum httpmethod {
  get, post;
}

httpheader.java

package demo;

import java.util.hashmap;
import java.util.map;

/**
 * 请求头
 */
public class httpheader {
  private map<string, string> params = new hashmap<string, string>();
    
  public httpheader addparam(string name, string value) {
    this.params.put(name, value);
    return this;
  }
  
  public map<string, string> getparams() {
    return this.params;
  }
}

httpparamers.java

package demo;

import java.io.ioexception;
import java.net.urlencoder;
import java.util.hashmap;
import java.util.map;
import java.util.set;

import com.alibaba.fastjson.json;

/**
 * 请求参数
 */
public class httpparamers {
  private map<string, string> params = new hashmap<string, string>();
  private httpmethod httpmethod;
  private string jsonparamer = "";

  public httpparamers(httpmethod httpmethod) {
    this.httpmethod = httpmethod;
  }

  public static httpparamers httppostparamers() {
    return new httpparamers(httpmethod.post);
  }

  public static httpparamers httpgetparamers() {
    return new httpparamers(httpmethod.get);
  }
  
  public httpparamers addparam(string name, string value) {
    this.params.put(name, value);
    return this;
  }

  public httpmethod gethttpmethod() {
    return this.httpmethod;
  }

  public string getquerystring(string charset) throws ioexception {
    if ((this.params == null) || (this.params.isempty())) {
      return null;
    }
    stringbuilder query = new stringbuilder();
    set<map.entry<string, string>> entries = this.params.entryset();

    for (map.entry<string, string> entry : entries) {
      string name = entry.getkey();
      string value = entry.getvalue();
      query.append("&").append(name).append("=").append(urlencoder.encode(value, charset));
    }
    return query.substring(1);
  }

  public boolean isjson() {
    return !isempty(this.jsonparamer);
  }

  public map<string, string> getparams() {
    return this.params;
  }

  public string tostring() {
    return "httpparamers " + json.tojsonstring(this);    
  }

  public string getjsonparamer() {
    return this.jsonparamer;
  }
  
  public void setjsonparamer() {
    this.jsonparamer = json.tojsonstring(this.params);
  }
  
  private static boolean isempty(charsequence cs) {
    return (cs == null) || (cs.length() == 0);
  }
}

httpclient.java

package demo;

import java.io.ioexception;
import java.util.map;
import java.util.set;

import org.apache.http.httpentity;
import org.apache.http.client.methods.closeablehttpresponse;
import org.apache.http.client.methods.httpget;
import org.apache.http.client.methods.httppost;
import org.apache.http.client.methods.httprequestbase;
import org.apache.http.entity.stringentity;
import org.apache.http.impl.client.closeablehttpclient;
import org.apache.http.impl.client.httpclients;
import org.apache.http.protocol.http;
import org.apache.http.util.entityutils;

public class httpclient {
  public static final string default_charset = "utf-8";
  public static final string json_content_form = "application/json;charset=utf-8";
  public static final string content_form = "application/x-www-form-urlencoded;charset=utf-8";
  
  public static string doservice(string url, httpparamers paramers, httpheader header, int connecttimeout, int readtimeout) throws exception {
    httpmethod httpmethod = paramers.gethttpmethod();
    switch (httpmethod) {
      case get:
        return doget(url, paramers, header, connecttimeout, readtimeout);
      case post:
        return dopost(url, paramers, header, connecttimeout, readtimeout);
    }
    return null;
  }
  
  /**
   * post方法
   * @param url
   * @param paramers
   * @param header
   * @param connecttimeout
   * @param readtimeout
   * @return
   * @throws ioexception
   */
  public static string dopost(string url, httpparamers paramers, httpheader header, int connecttimeout, int readtimeout) throws ioexception {
    string responsedata = "";
    closeablehttpclient httpclient = null;
    closeablehttpresponse httpresponse = null;    
    try{
      string query = null;          
      httppost httppost = new httppost(url);
      setheader(httppost, header);            
      if (paramers.isjson()) {
        //json数据
        httppost.setheader(http.content_type, json_content_form);        
        query = paramers.getjsonparamer();
      } else {
        //表单数据
        httppost.setheader(http.content_type, content_form);
        query = paramers.getquerystring(default_charset);
      }
      if(query != null){
        httpentity reqentity = new stringentity(query);
        httppost.setentity(reqentity);
      }      
      httpclient = httpclients.createdefault();            
      httpresponse = httpclient.execute(httppost);
      httpentity resentity = httpresponse.getentity();
      responsedata = entityutils.tostring(resentity);
    } catch (exception e){
      e.printstacktrace();
    } finally{
      httpresponse.close();
      httpclient.close();
    }
    return responsedata;
  }
  
  
  /**
   * get方法
   * @param url
   * @param params
   * @param header
   * @param connecttimeout
   * @param readtimeout
   * @return
   * @throws ioexception
   */
  public static string doget(string url, httpparamers params, httpheader header, int connecttimeout, int readtimeout) throws ioexception {
    string responsedata = "";
    closeablehttpclient httpclient = null;
    closeablehttpresponse httpresponse = null;    
    try{  
      string query = params.getquerystring(default_charset);  
      url = buildgeturl(url, query);
      httpget httpget = new httpget(url);
      setheader(httpget, header);  
      httpclient = httpclients.createdefault();            
      httpresponse = httpclient.execute(httpget);
      httpentity resentity = httpresponse.getentity();
      responsedata = entityutils.tostring(resentity);
    } catch (exception e){
      e.printstacktrace();
    } finally{
      httpresponse.close();
      httpclient.close();
    }
    return responsedata;
  }
  
  private static void setheader(httprequestbase httprequestbase, httpheader header){
    if(header != null){
      map<string,string> headermap = header.getparams();
      if (headermap != null && !headermap.isempty()) {    
        set<map.entry<string, string>> entries = headermap.entryset();  
        for (map.entry<string, string> entry : entries) {
          string name = entry.getkey();
          string value = entry.getvalue();
          httprequestbase.setheader(name, value);
        }
      }
    }
  }
  
  private static string buildgeturl(string url, string query) throws ioexception {
    if (query == null || query.equals("")) {
      return url;
    }
    stringbuilder newurl = new stringbuilder(url);
    boolean hasquery = url.contains("?");
    boolean hasprepend = (url.endswith("?")) || (url.endswith("&"));
    if (!hasprepend) {
      if (hasquery) {
        newurl.append("&");
      } else {
        newurl.append("?");
        hasquery = true;
      }
    }
    newurl.append(query);
    hasprepend = false;
    return newurl.tostring();
  }
}

httpservice.java

package demo;

import java.util.map;

import com.alibaba.fastjson.jsonobject;
import com.alibaba.fastjson.typereference;

public class httpservice {
  private string serverurl;
  private int connecttimeout = 15000;
  private int readtimeout = 30000;
  public httpservice(string serverurl) {
    this.serverurl = serverurl.trim();
  }
  public map<string, object> commonservice(string serviceurl, httpparamers paramers) throws exception{
    return commonservice(serviceurl, paramers, null);
  }
  public map<string, object> commonservice(string serviceurl, httpparamers paramers, httpheader header) throws exception{
    string response = service(serviceurl, paramers, header);
    try {
      map<string, object> result = jsonobject.parseobject(response, new typereference<map<string, object>>() {});
      if ((result == null) || (result.isempty())) {
        throw new exception("远程服务返回的数据无法解析");
      }
      integer code = (integer) result.get("code");
      if ((code == null) || (code.intvalue() != 0)) {
        throw new exception((string) result.get("message"));
      }
      return result;
    } catch (exception e) {
      throw new exception("返回结果异常,response:" + response, e);
    }
  }
  public string service(string serviceurl, httpparamers paramers) throws exception {
    return service(serviceurl, paramers, null);
  }
  public string service(string serviceurl, httpparamers paramers, httpheader header) throws exception {
    string url = this.serverurl + serviceurl;
    string responsedata = "";
    try {
      responsedata = httpclient.doservice(url, paramers, header, this.connecttimeout, this.readtimeout);
    } catch (exception e) {
      throw new exception(e.getmessage(), e);
    }
    return responsedata;
  }
  
  public string getserverurl() {
    return this.serverurl;
  }

  public int getconnecttimeout() {
    return this.connecttimeout;
  }

  public int getreadtimeout() {
    return this.readtimeout;
  }

  public void setconnecttimeout(int connecttimeout) {
    this.connecttimeout = connecttimeout;
  }

  public void setreadtimeout(int readtimeout) {
    this.readtimeout = readtimeout;
  }
}

测试例子test1.java

package demo;

import org.junit.ignore;
import org.junit.test;

public class test1 {

  //免费的在线rest服务, 提供测试用的http请求假数据
  //接口信息说明可见：http://www.hangge.com/blog/cache/detail_2020.html
  string uri = "http://jsonplaceholder.typicode.com";
  
  //get方式请求数据
  //请求地址：http://jsonplaceholder.typicode.com/posts
  @ignore("暂时忽略")
  @test
  public void test1() {
    system.out.print("\n" + "test1---------------------------"+ "\n");
    httpparamers paramers = httpparamers.httpgetparamers();
    string response = "";
    try {
      httpservice httpservice = new httpservice(uri);
      response = httpservice.service("/posts", paramers);      
    } catch (exception e) {
      e.printstacktrace();
    }
    system.out.print(response);
  }
  
  //get方式请求数据
  //请求地址：http://jsonplaceholder.typicode.com/posts?userid=5
  @ignore("暂时忽略")
  @test
  public void test2() {
    system.out.print("\n" + "test2---------------------------"+ "\n");
    httpparamers paramers = httpparamers.httpgetparamers();
    paramers.addparam("userid", "5");
    string response = "";
    try {
      httpservice httpservice = new httpservice(uri);      
      response = httpservice.service("/posts", paramers);      
    } catch (exception e) {
      e.printstacktrace();
    }
    system.out.print(response);
  }
  
  //post方式请求数据
  //请求地址：http://jsonplaceholder.typicode.com/posts  
  @test
  public void test3() {
    system.out.print("\n" + "test3---------------------------"+ "\n");
    httpparamers paramers = httpparamers.httppostparamers();
    paramers.addparam("time", string.valueof(system.currenttimemillis()));
    string response = "";
    try {
      httpservice httpservice = new httpservice(uri);
      response = httpservice.service("/posts", paramers);      
    } catch (exception e) {
      e.printstacktrace();
    }
    system.out.print(response);
  }
}

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